JP2011000765A - Interior material for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interior material for a vehicle equipped with a skin layer in which no wrinkle or the like is caused and which has excellent light resistance, tensile characteristics, abrasion resistance or the like.SOLUTION: The interior material for the vehicle 100 is equipped with the skin layer 111 and a base material layer 13a. The skin layer contains an olefinic thermoplastic elastomer (EPDM etc.), a polyolefin resin (a polypropylene resin etc.), a polylactic acid resin and a styrenic thermoplastic elastomer (SEBS etc.). When the sum of the elastomers and the resins is made to be 100 mass%, the olefinic thermoplastic elastomer is 20 to 70 mass%, the polyolefin resin is 10 to 50 mass%, the polylactic acid resin is 5 to 30 mass% and the styrenic thermoplastic elastomer is 5 to 30 mass%.

Description

  The present invention relates to a vehicle interior material. More specifically, the interior of a vehicle is made of a thermoplastic elastomer and a polylactic acid resin that is a plant-derived material, and has a skin layer that is free of wrinkles and has excellent light resistance, tensile properties, wear resistance, and the like. Regarding materials.

  Thermoplastic elastomers used in the manufacture of skin materials for vehicle interior materials are known as materials preferable from the viewpoint of the environment as compared with conventional vinyl chloride resins (see, for example, Patent Document 1). In the automotive interior and exterior parts described in Patent Document 1, a thermoplastic elastomer such as a specific styrene-based thermoplastic elastomer is used, but all of the raw materials are materials derived from petroleum. On the other hand, in view of the recent problem of global warming, there is a growing need to use plant-derived materials and reduce the amount of carbon dioxide generated based on the so-called carbon neutral concept. The use of plant-derived materials is necessary for the production of wood and the like.

JP-A-2005-231134

  As described above, it is necessary to use plant-derived materials, but polylactic acid resins often used as plant-derived materials are hard resins and are used as they are as raw materials for skin materials that require flexibility. Is a problem. In addition, it is not easy to uniformly mix the polylactic acid resin with the thermoplastic elastomer, and if it is not uniformly dispersed and mixed, the skin material may be drawn down during molding and wrinkles may occur in the product. Decrease in physical properties such as light resistance, tensile properties such as tensile strength, and abrasion resistance may be a problem. Furthermore, if all of the raw materials are petroleum-derived materials, as in the automobile interior and exterior parts described in Patent Document 1, there is no such problem as described above, but the generation of carbon dioxide during disposal is avoided. Therefore, it is not preferable from the viewpoint of environment.

  The present invention has been made in view of the above-described state of the art, and is made of a thermoplastic elastomer and a polylactic acid resin that is a plant-derived material. An object of the present invention is to provide an interior material for a vehicle having a skin layer that has excellent light resistance and has sufficient tensile properties and wear resistance in spite of containing a polylactic acid resin. And

The present invention is as follows.
1. A vehicle interior material comprising a skin layer and a base material layer, wherein the skin layer contains an olefinic thermoplastic elastomer, a polyolefin resin, a polylactic acid resin, and a styrene thermoplastic elastomer, and the olefinic thermoplastic elastomer , When the total of the polyolefin resin, the polylactic acid resin and the styrene-based thermoplastic elastomer is 100% by mass, the olefin-based thermoplastic elastomer is 20-70% by mass, the polyolefin resin is 10-50% by mass, The interior material for vehicles, wherein the polylactic acid resin is 5 to 30% by mass and the styrene-based thermoplastic elastomer is 5 to 30% by mass.
2. The base layer contains natural fibers and at least one of a polylactic acid resin and a polyolefin resin. The vehicle interior material described in 1.
3. 2. The cross-linked foam layer is provided between the skin layer and the base material layer. The vehicle interior material described in 1.
4). The substrate layer includes a polyurethane foam layer. The vehicle interior material described in 1.
5. The polyurethane foam layer is formed by using a plant-derived raw material. The vehicle interior material described in 1.
6). 3. The support layer is mounted on the surface of the polyurethane foam layer opposite to the surface on which the skin layer is laminated. Or 5. The vehicle interior material described in 1.

According to the vehicle interior material of the present invention, since a predetermined amount of a specific thermoplastic elastomer or the like is used together with the polylactic acid resin, a polylactic acid resin that is not easily uniformly mixed with the thermoplastic elastomer or the like is obtained. It can be uniformly dispersed and mixed. Therefore, it can be set as the vehicle interior material provided with the skin layer which does not generate wrinkles and has excellent light resistance, tensile properties, wear resistance, and the like. Moreover, since the polylactic acid resin which is a plant-derived material is used, it can be set as the interior material for vehicles provided with a preferable skin layer also from an environmental viewpoint.
Moreover, when the base material layer contains natural fibers and at least one of a polylactic acid resin and a polyolefin resin, it can be used as a vehicle interior material having sufficient rigidity and the like. Since natural fibers are contained, the vehicle interior material can be more preferable from the viewpoint of environment.
Further, when a cross-linked foam layer is provided between the skin layer and the base material layer, the skin layer and the base material layer can be bonded more firmly, and are flexible and have excellent tactile sensation. It can be used as an interior material.
Moreover, when a base material layer is equipped with a polyurethane foam layer, this polyurethane foam layer becomes a bad layer, has excellent cushioning properties, and can be used as a vehicle interior material suitable for a seat for seating or the like.
Furthermore, when the polyurethane foam layer is made of a plant-derived raw material, the base material layer is also formed of a material preferable from the viewpoint of the environment, and can be a more preferable vehicle interior material.
In addition, when a support layer is mounted on the surface of the polyurethane foam layer opposite to the surface on which the skin layer is laminated, the interior material for a vehicle should be flexible and have sufficient rigidity. The vehicle interior material is easy to manufacture because it uses a support plate that can be used and has sufficient strength and is easy to handle.

It is a schematic diagram of the cross section of the interior material for vehicles of this invention provided with a crosslinked foam layer. It is a schematic diagram of a cross section of another vehicle interior material of the present invention in which the base material layer is a polyurethane foam layer and includes a support layer. It is typical explanatory drawing of a process when manufacturing the vehicle interior material of FIG. 1 by the vacuum forming method. It is typical explanatory drawing of the formation process in the case of providing the embossed pattern of a skin layer at the time of vacuum forming. It is typical explanatory drawing of a formation process when manufacturing the interior material for vehicles of Drawing 2 by an integral foaming method.

Hereinafter, the present invention will be described in detail with reference to the drawings.
The vehicle interior material of the present invention includes a skin layer and a base material layer, and the skin layer contains an olefin-based thermoplastic elastomer, a polyolefin resin, a polylactic acid resin, and a styrene-based thermoplastic elastomer, and includes an elastomer and a resin. When the total is 100% by mass, the olefinic thermoplastic elastomer is 20 to 70% by mass, the polyolefin resin is 10 to 50% by mass, the polylactic acid resin is 5 to 30% by mass, and the styrene thermoplastic elastomer is 5 to 30%. % By mass.

[1] Skin Layer The “skin layer” is formed using an olefinic thermoplastic elastomer, polyolefin resin, polylactic acid resin, and styrene thermoplastic elastomer as essential raw materials. The outer surface of the skin layer becomes the design surface of the vehicle interior material.

  The “olefin-based thermoplastic elastomer” is not particularly limited, and examples thereof include an olefin-based thermoplastic elastomer in which a rubber component serving as a soft segment is dispersed and contained in an olefin-based resin component serving as a hard segment. The olefin resin component includes an olefin homopolymer and an olefin copolymer having 70 mol% or more (in some cases 100 mol%) of olefin units when the total amount of structural units is 100 mol%. Can be mentioned. Examples of the homopolymer include polyethylene and polypropylene. Examples of the copolymer include an ethylene / propylene random copolymer, an ethylene / propylene block copolymer, an ethylene / vinyl acetate copolymer, and an ethylene / alkyl acrylate copolymer. These olefin resin components may be used alone or in combination of two or more.

  On the other hand, the rubber component is not particularly limited, and examples thereof include olefin rubber, styrene rubber, urethane rubber, acrylic rubber, and the like, and olefin rubber and styrene rubber are preferable. These rubber components may be contained alone or in combination of two or more.

Examples of olefin rubbers include ethylene / propylene copolymer rubber (EPR), ethylene / propylene / non-conjugated diene copolymer rubber (EPDM), ethylene / 1-butene copolymer rubber, and ethylene / 1-butene / non-conjugated diene copolymer. Examples thereof include rubber, ethylene / propylene / 1-butene copolymer rubber, ethylene / 1-hexene copolymer rubber, ethylene / vinyl acetate copolymer rubber, and ethylene / acrylic acid copolymer rubber. These copolymer rubbers may be any of random copolymer rubber, block copolymer rubber, and graft copolymer rubber. Non-conjugated dienes include 5-ethylidene-2-norbornene, 1,4-hexadiene, dicyclopentadiene, dicyclooctadiene, 1,2-butadiene and the like. These olefinic rubbers may be contained alone or in combination of two or more.
The olefin rubber usually has 50 mol% or more of olefin units when the total amount of the structural units is 100 mol%. However, it does not have an aromatic vinyl compound unit such as a styrene unit or if it has 5 mol% or less.

Styrene rubbers include styrene / butadiene / styrene block copolymer rubber, styrene / isoprene / styrene block copolymer rubber, styrene / ethylene / butylene / styrene block copolymer rubber, styrene / ethylene / propylene / styrene block copolymer rubber, Examples thereof include styrene / butadiene random copolymer rubber, styrene / butadiene copolymer rubber, and hydrogenated products of these rubbers. These styrene rubbers may be contained alone or in combination of two or more.
The styrene rubber usually contains an aromatic vinyl compound unit exceeding 5 mol% when the total amount of the structural units is 100 mol%.

  As the olefinic thermoplastic elastomer, an elastomer in which an olefinic rubber component is dispersed and contained in an olefinic resin component is preferable. In this case, the olefin resin component is preferably at least one of polyethylene, polypropylene, and ethylene / propylene copolymer, and particularly preferably ethylene / propylene copolymer. Moreover, as an olefin type rubber component, EPR and / or EPDM are preferable.

  In the olefinic thermoplastic elastomer in which the olefinic rubber component is dispersed and contained in the olefinic resin component, the olefinic resin component and the olefinic rubber component may be cross-linked or not cross-linked. Although it is good, it is preferable that at least a part is crosslinked. Furthermore, in this elastomer, when the whole is 100% by mass, the olefinic rubber component is preferably 90% by mass or less. When the content of the olefin rubber component is 90% by mass or less, the resin component and the rubber component can be mixed more easily.

  Specific examples of olefinic thermoplastic elastomers are: Mitsui Chemicals, trade name “Miralastomer”, Mitsui Chemicals, trade name “Toughmer”, Mitsubishi Chemical, trade name “Thermo Run”, Mitsubishi Chemical Name "Zeras", manufactured by Sumitomo Chemical Co., Ltd., trade name "Esporex TPE", manufactured by Sumitomo Chemical Co., Ltd., trade name "Tough Selenium", manufactured by JSR, trade name "Exelink", manufactured by AES Japan Co., Ltd., trade name "Santoprene" Or the like. One type of these elastomers may be contained, or two or more types may be contained.

  The “polyolefin resin” is not particularly limited, but is a resin having an olefin unit as a main constituent unit. This resin usually has 80 mol% or more of olefin units when the total amount of the structural units is 100 mol%. Examples of olefins used in the production of this resin include ethylene and propylene, 1-butene, 1-pentene, 1-hexene, 2-methyl-1-propene, 3-methyl-1-pentene, and 4-methyl-1 -Pentene, 5-methyl-1-hexene and the like. These olefins may be used alone or in combination of two or more.

  The structural unit of the polyolefin resin is preferably an ethylene unit and / or a propylene unit. Further, when the total amount of the structural units is 100 mol%, the total of ethylene units and propylene units is 80 mol% or more, particularly 85 mol%, more preferably 90 mol% or more (100 mol%, that is, polyethylene, polypropylene, ethylene). / Propylene copolymer may be used). Furthermore, when it has two or more kinds of structural units, that is, when it is a copolymer, it may be a random copolymer (for example, ethylene / propylene random copolymer), or a block copolymer (for example, Ethylene / propylene block copolymer).

  The “polylactic acid resin” is a resin mainly composed of lactic acid units and / or lactide units (hereinafter, these may be simply referred to as “lactic acid units”). Lactic acid includes L-lactic acid and D-lactic acid, and lactide includes L-lactide, D-lactide, meso-lactide and DL-lactide. These may be used alone or in combination of two. May be. The ratio of lactic acid units is not particularly limited, but when the total amount of the structural units of the polylactic acid resin is 100 mol%, the lactic acid units are usually 70 mol% or more (may be 100 mol%). It is preferable that

  When having other structural units other than lactic acid units, these other structural units are usually 30 mol% or less and 10 mol% or less (when the total amount of the structural units of the polylactic acid resin is 100 mol%) When it has other structural units, it is preferably 1 mol% or more). Examples of other structural units include polyvalent carboxylic acids such as oxalic acid, malonic acid, and succinic acid, polyhydric alcohols such as ethylene glycol and propylene glycol, and lactones such as glycolide and ε-caprolactone. Can be mentioned. These other monomers may be used alone or in combination of two or more.

  Furthermore, a polylactic acid resin and another resin can be used in combination. The other resin is not particularly limited as a polyester resin, but poly-ε-caprolactone, poly-β-propiolactone, Examples thereof include polyester resins such as poly-β-butyrolactone, poly-γ-butyrolactone, polyglycolic acid, polymalic acid, polyethylene succinate, polybutylene succinate, butylene succinate / adipate copolymer resin. These polyester resins may be used alone or in combination of two or more.

  The “styrenic thermoplastic elastomer” is a copolymer having a structural unit derived from an aromatic vinyl compound, and this structural unit is usually contained as an aromatic vinyl polymer block and becomes a hard segment. Further, the styrene thermoplastic elastomer may be hydrogenated or not hydrogenated, but particularly when used in combination with an olefin thermoplastic resin, a hydrogenated styrene thermoplastic elastomer is used. It is preferable to use it.

The aromatic vinyl compound is not particularly limited, and alkyl-substituted styrene such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, vinylanthracene, etc. Is mentioned. As the aromatic vinyl compound, styrene is particularly preferable. These aromatic vinyl compounds may be used alone or in combination of two or more.
The styrenic thermoplastic elastomer usually has a structural unit derived from an aromatic vinyl compound in an amount of 5 mol% or more (usually 80 mol% or less) when the total amount of the structural units is 100 mol%.

  In addition, the other constituent parts excluding the aromatic vinyl polymer block serving as a hard segment may be formed using any monomer as long as it exhibits elastomeric properties and functions as a soft segment. Usually formed using conjugated dienes. Examples of the conjugated diene include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like. These conjugated dienes may be used alone or in combination of two or more.

  As the styrenic thermoplastic elastomer, a hydrogenated elastomer and / or a non-hydrogenated elastomer can be used. Hydrogenated styrene thermoplastic elastomers include hydrogenated styrene / butadiene copolymers such as hydrogenated styrene / butadiene random copolymers, and hydrogenated styrene / ethylene / propylene / styrene block copolymers. Examples thereof include styrene / isoprene copolymers, hydrogenated styrene / ethylene / butene / styrene block copolymers. On the other hand, non-hydrogenated styrenic thermoplastic elastomers include styrene / butadiene copolymers such as styrene / butadiene / styrene block copolymers and styrene / isoprene copolymers such as styrene / isoprene / styrene block copolymers. Examples include coalescence.

  Specific examples of styrenic thermoplastic elastomers include: Asahi Kasei Co., Ltd., trade name “Tuftec” (Tuftec H series and Tuftec P series), Asahi Kasei Co., Ltd., trade name “Tufprene”, Asahi Kasei Co., Ltd., trade name “Asaprene”, Made by Asahi Kasei Co., Ltd., trade name “Sorprene”, Kuraray Co., Ltd., trade name “Septon”, Kuraray Co., Ltd., trade name “Hibler”, made by Clayton Polymer Japan Co., Ltd., trade name “Clayton G”, made by JSR, trade name "Dynalon", manufactured by JSR, trade name "JSR-TR", manufactured by JSR, trade name "JSR-SIS", manufactured by Sumitomo Chemical Co., Ltd., trade name "Esporex SB", manufactured by Mitsubishi Chemical Corporation, trade name "Lavalon" ”, Manufactured by Denki Kagaku Co., Ltd., trade name“ Electrified STR ”, manufactured by Zeon Corporation, trade name“ Quintac ”, manufactured by Kentechnos Co., Ltd.,“ Reostomari ”, etc. It is. These elastomers may be used alone or in combination of two or more.

  The skin layer can contain other components excluding the elastomer and the resin. The content of these other components is not particularly limited, but normally it is preferably 10 parts by mass or less when the total of the elastomer and the resin is 100 parts by mass. Other components include various antioxidants such as phenols and phosphorus, various light stabilizers such as hindered amines, various ultraviolet absorbers such as benzotriazoles, lubricants such as stearic acid compounds, and antistatic agents. Softeners such as mineral oil and process oil, fillers such as plasticizers, pigments and talc, flame retardants, flame retardant aids, antibacterial agents, and deodorants. These other components may be used alone or in combination of two or more.

  As described above, the skin layer contains an olefin-based thermoplastic elastomer, a polyolefin resin, a polylactic acid resin, and a styrene-based thermoplastic elastomer, and the content of each elastomer and resin is a total of 100 of these elastomers and resins. In the case of mass%, the olefin thermoplastic elastomer is 20 to 70 mass%, the polyolefin resin is 10 to 50 mass%, the polylactic acid resin is 5 to 30 mass%, and the styrene thermoplastic elastomer is 5 to 30 mass%. is there. The olefinic thermoplastic elastomer is preferably 35 to 65% by mass, the polyolefin resin is 15 to 45% by mass, the polylactic acid resin is 5 to 20% by mass, and the styrene thermoplastic elastomer is preferably 5 to 20% by mass, More preferably, the olefinic thermoplastic elastomer is 40 to 60% by mass, the polyolefin resin is 20 to 40% by mass, the polylactic acid resin is 5 to 15% by mass, and the styrene thermoplastic elastomer is 5 to 15% by mass.

  If the olefinic thermoplastic elastomer is 20 to 70% by mass, the polyolefin resin is 10 to 50% by mass, the polylactic acid resin is 5 to 30% by mass, and the styrene thermoplastic elastomer is 5 to 30% by mass, the styrene thermoplasticity The elastomer acts satisfactorily as a compatibilizing agent, and the other three types of elastomers and resins, which are usually not easily dispersed and mixed, can be uniformly dispersed and mixed. Moreover, generation | occurrence | production of a flaw is prevented and the fall of physical properties, such as light resistance, a tensile characteristic, and abrasion resistance, is also suppressed. Furthermore, the use of a petroleum-derived material can be reduced by using a polylactic acid resin, which is preferable from the viewpoint of the environment.

  The thickness of the skin layer is not particularly limited, but can be 0.2 to 1.5 mm. If the thickness of the skin layer is 0.2 to 1.5 mm, the skin material that becomes the skin layer after molding has sufficient strength and the like and has excellent shapeability at the time of vacuum molding or the like. preferable. Moreover, it can be set as the skin layer which has the high durability especially with respect to a scratch, a stab, etc., and has a characteristic suitable as a vehicle interior material. The thickness of the skin layer is preferably 0.3 to 1.4 mm, particularly 0.4 to 1.3 mm.

  The hardness of the skin layer is not particularly limited, but the Shore A hardness is preferably 70 to 90. A Shore A hardness of 70 to 90 is preferable because the skin material that becomes the skin layer after molding has sufficient strength and the like and has excellent formability during vacuum molding or the like. Moreover, it can be set as the skin layer which has the high durability especially with respect to a scratch, a stab, etc., and has a characteristic suitable as a vehicle interior material. The Shore A hardness is more preferably 75 to 85, particularly 77 to 83.

  Furthermore, the skin layer may have a concavo-convex pattern (see the embossed pattern 11a in FIGS. 1 and 2) molded on its outer surface (the surface that becomes the design surface of the vehicle interior material). Examples of the uneven pattern include a wrinkle pattern, a satin pattern, a hairline pattern, and the like. Only one type of these uneven patterns may be provided, or two or more types may be provided. The concavo-convex pattern can be formed by pressing the skin material on a roll having a concavo-convex pattern on the peripheral surface and transferring the concavo-convex pattern. It can also be formed by molding, and can be formed by pressing one surface of a heated skin material against a mold provided with a concavo-convex pattern and transferring the concavo-convex pattern. When the skin layer has a concavo-convex pattern, a beautiful design surface can be obtained due to the decorative effect, the tactile sensation of the skin layer is improved, and the friction resistance is also improved.

  The manufacturing method of the skin material used as the skin layer of the vehicle interior material by vacuum forming or the like is not particularly limited, and can be manufactured by a known method. For example, it can be manufactured by a method of forming with an extruder having a T-die attached thereto, a calendar forming method, or the like. Further, the skin material can be uniaxially or biaxially stretched as necessary to improve the tensile strength and the like.

[2] Base material layer (1) Base material layer made of thermoplastic resin The “base material layer” is a layer that supports the skin layer, and can be easily molded as a base material for a vehicle interior material. It is only necessary to have sufficient rigidity and the like, and is not particularly limited. As this base material layer, a base material layer using at least a thermoplastic resin can be used from the viewpoints of moldability, physical properties, and the like.

  The thermoplastic resin used for forming the base material layer is not particularly limited, and various thermoplastic resins can be used. The thermoplastic resin includes polyolefin resin, polyester resin, polystyrene resin, acrylic resin, polyamide resin, polycarbonate resin, polyacetal resin, ABS resin (acrylonitrile / butadiene / styrene copolymer resin), and MBS resin (methyl methacrylate / butadiene / Styrene copolymer resin). Of these thermoplastic resins, polyolefin resins and polyester resins are preferred. Only one thermoplastic resin may be used, or two or more thermoplastic resins may be used in combination.

  As polyolefin resin, the various polyolefin resin illustrated as polyolefin resin used for formation of the said skin layer can be used without being specifically limited. Further, as described above, a polyolefin resin having an ethylene unit and / or a propylene unit is preferable, and the total of the ethylene unit and the propylene unit is 80 mol% or more, particularly 85 mol%, more preferably 90 mol% or more (100 mol%, that is, , Polyethylene, polypropylene, ethylene / propylene random copolymer, or ethylene / propylene block copolymer may be particularly preferable. The polyolefin resin may be the same as or different from the polyolefin resin used for forming the skin layer.

  Examples of the polyester resin include aromatic polyester resins and aliphatic polyester resins. Examples of the aromatic polyester resin include polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. Moreover, polylactic acid resin etc. are mentioned as an aliphatic polyester resin. This polylactic acid resin can use a natural material as a raw material, and is preferable from an environmental viewpoint. Moreover, it can also be set as the base material layer which has the outstanding mechanical characteristic, durability, etc. As the polylactic acid resin, various polylactic acid resins exemplified as the polylactic acid resin used for forming the skin layer can be used without particular limitation. These polyester resins may be used alone or in combination of two or more.

  Furthermore, natural materials such as natural fibers and non-fibrous plant materials can be used together with the thermoplastic resin for forming the base material layer. Among these, examples of natural fibers include vegetable fibers, protein fibers such as animal hair fibers and silk fibers, and vegetable fibers are preferred. In addition, examples of the non-fibrous plant material include a material obtained by subdividing a woody part of a plant. That is, a crushed material and a pulverized material of a wood part can be used. More specifically, kenaf core, wood flour and the like can be mentioned. These may be used alone or in combination of two or more.

  Plant fibers include kenaf, jute hemp, manila hemp, sisal hemp, husk, cocoon, cocoon, banana, pineapple, coconut palm, corn, sugar cane, bagasse, palm, papyrus, cocoon, esparto, sabygrass, wheat, rice, bamboo, Examples thereof include fibers of various plants such as conifers such as cedar and cypress, broadleaf trees, and cotton. These vegetable fibers may be used alone or in combination of two or more.

  The plant part used as the plant fiber is not particularly limited as long as the fiber can be collected, and may be any part of the non-wood part, stem part, root part, leaf part, wood part, etc., and two or more different parts. Fibers may be collected from the site. As fibers collected from each part, bast fibers (kenaf, roselle, asa, flax, ramie, jute, hemp, etc.), seed hair fibers (cotton, etc.), leaf vein fibers (manila hemp, sisal hemp, etc.) and fruits Examples thereof include fibers (coconut and the like).

  As a plant that collects plant fiber, it is an annual plant that grows quickly and has excellent carbon dioxide absorption, so it can contribute to reducing the amount of carbon dioxide in the atmosphere and effectively using forest resources. Kenaf is preferred. Furthermore, the bunch of kenaf contains a cellulose content at a high rate of 60% by mass or more, and kenaf fibers collected from kenaf bast are particularly preferable as plant fibers. This kenaf is a fast-growing annual grass with a woody stem and is a plant classified as a mallow. Hibiscus cannabinus and hibiscus sabdariffa in scientific names, and red, hemp, cuban kenaf, western hemp, taikenaf, mesta, bimli, umbari and Bombay hemp in common names.

  The average fiber length and average fiber diameter of natural fibers, particularly vegetable fibers, are not particularly limited, but an average fiber length of 10 mm or more is preferable because a base material layer having excellent mechanical properties can be obtained. The average fiber length is 10 to 150 mm, particularly 20 to 100 mm, and more preferably 30 to 80 mm. This average fiber length is in accordance with JIS L1015. Single fibers are randomly picked up one by one by the direct method, stretched straight without stretching, the fiber length is measured on a measuring scale, and a total of 200 fibers are measured. The average value. On the other hand, an average fiber diameter of 1 mm or less is preferable because a base material layer having excellent mechanical properties can be obtained. The average fiber diameter is 0.01 to 1 mm, particularly 0.05 to 0.7 mm, and more preferably 0.07 to 0.5 mm. This average fiber diameter is an average value measured for a total of 200 fibers by taking out single fibers at random and measuring the fiber diameter at the center in the length direction of the fibers using an optical microscope.

  Natural fibers and non-fibrous plant materials can be pretreated with a coupling agent having a reactive functional group for the purpose of improving the affinity with the thermoplastic resin used in combination. Examples of the coupling agent include isocyanate compounds, organic silane compounds, organic titanate compounds, acrylic compounds, and epoxy compounds.

  When a thermoplastic resin and natural fibers, particularly vegetable fibers, are used in combination for forming the base material layer, the amount of each is not particularly limited, and the total of the thermoplastic resin and natural fibers is 100% by mass. The thermoplastic resin can be 5 to 90% by mass, particularly 10 to 80% by mass, and further 20 to 70% by mass. Moreover, when using a polypropylene resin as a thermoplastic resin and using a kenaf fiber as a natural fiber, when the total of the polypropylene resin and the kenaf fiber is 100% by mass, the polypropylene resin is 10 to 90% by mass, In particular, it can be 20 to 80% by mass, and further 30 to 70% by mass.

  The thickness of the base material layer is not particularly limited, but is preferably 10 mm or less. If the thickness of the base material layer is 10 mm or less, for example, during vacuum forming, the equipment used as the base material layer has excellent formability and sufficiently supports other layers such as the skin layer. It is possible to provide a vehicle interior material having sufficient mechanical properties as well as a support layer that can be used. This thickness is more preferably 0.1 to 5.0 mm, particularly 1.0 to 3.0 mm.

  The formation method of a base material layer is not specifically limited. The base material layer is, for example, (a) heat-compressing a fiber mat formed by a method of mixing and depositing thermoplastic resin fibers and natural fibers by an airlay method, and (b) a thermoplastic resin as a medium. A dispersion liquid such as emulsion, suspension, etc., in which water is dispersed is sprayed on natural fibers, impregnated with resin, heated, dried, and then heat-compressed with a resin-impregnated fiber mat deposited by the airlaid method or the like. (C) A nonwoven fabric made of natural fibers is immersed in a dispersion liquid such as an emulsion or suspension in which a thermoplastic resin is dispersed in a medium, and then a resin-impregnated fiber mat formed by drying is heated and compressed. It can be formed by a method. Any of these forming methods (a) to (c) may be employed, or two or more methods may be used in combination. Furthermore, the base material layer may be formed by other methods.

  Among the forming methods (a) to (c), the methods (b) and (c) that can more uniformly disperse the natural fibers and the thermoplastic resin contained in the fiber mat are preferable. In addition, the method (a) is preferable because the process is simplified, the production cost can be kept low, the productivity is high, and it is suitable for mass production. Among these forming methods, the method (a) which has high productivity and is suitable for mass production is more preferable.

  Furthermore, in the case of the method (a), the method for mixing thermoplastic resin fibers and natural fibers is not particularly limited, and various fiber mixing methods such as the fleece method and the card method may be used in addition to the air array method. Can do. These mixing methods may be used alone or in combination of two or more. In addition, the fibers may be entangled after mixing, and the entanglement method is not particularly limited, but various entanglement methods such as a needle punch method and a stitch bond method can be used. These entanglement methods may be used alone or in combination of two or more. Furthermore, the conditions for heating and compressing the fiber mat are not particularly limited, and depending on the type of thermoplastic resin fiber and the like, for example, the temperature can be 170 to 240 ° C., and the pressure can be 1 to 2 MPa.

(2) Polyurethane foam layer The base material layer can also be formed of polyurethane foam. Since this base material layer is flexible and has excellent cushioning properties, it is suitable as a seat material among vehicle interior materials, and the polyurethane foam layer functions as a pad material for a vehicle seat.

The polyurethane foam layer can be formed using a foam raw material containing a polyol, a polyisocyanate, a crosslinking agent, a catalyst, a foaming agent, a foam stabilizer, and the like.
A polyol is not specifically limited, The various polyol used for manufacture of a polyurethane foam can be used. Moreover, a castor oil polyol derived from a plant can be used as the polyol, and it is preferable from the viewpoint of the environment to use a castor oil polyol. Furthermore, other polyols except for castor oil polyol preferably have an average functional group number of 2.0 to 6.0 and a hydroxyl value of 20 to 800 mgKOH / g. If such a polyol is used, a polyurethane foam layer having a small compression residual strain and excellent elongation can be obtained.

  Examples of the polyol include polyether polyol, polyester polyol, polymer polyol, polycarbonate polyol, poly (meth) acryl polyol and the like, and polyether polyol and polymer polyol are preferable. These polyols may be used alone or in combination of two or more.

  Examples of the polyether polyol include ethylene oxide (hereinafter abbreviated as “EO”), propylene oxide (hereinafter referred to as “PO”) using low molecular weight alcohols, amines, amino alcohols, and phenols as initiators. And a polyoxyethylene polyol, a polyoxypropylene polyol, a polyoxyethylene polyoxypropylene polyol, and the like obtained by addition polymerization. The polyether polyol is preferably a polyoxyethylene polyoxypropylene polyol, a polyol obtained by block addition polymerization of PO and EO, and a polyoxyethylene having a content of 5 to 50% by mass of an oxyethylene unit obtained by adding EO to the terminal. Oxyethylene polyoxypropylene polyol is preferred. When the content of the oxyethylene unit is 5 to 50% by mass, the foam raw material can be easily cured, and an open-cell foam can be obtained.

  The polymer polyol is a method of polymerizing an ethylenically unsaturated monomer such as styrene or acrylonitrile in a polyether polyol, a method of mixing separately produced polymer fine particles with a polyether polyol, a macromonomer having an ethylenically unsaturated group, It is produced by a method of polymerizing an ethylenically unsaturated monomer in a polyether polyol. Among these, a polyol obtained by polymerizing an ethylenically unsaturated monomer in a polyether polyol is preferred, and a polyol obtained by polymerizing an ethylenically unsaturated monomer in a polyoxypropylene triol is more preferred. In the method of mixing polymer fine particles, the content of the polymer fine particles is preferably 50 parts by mass or less, particularly preferably 30 parts by mass or less, when the polyether polyol is 100 parts by mass. When the content of the polymer fine particles exceeds 50 parts by mass, the viscosity of the polymer polyol becomes high and workability at the time of foam molding is lowered.

  Examples of the polyester polyol include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, trimellitic acid, and other polycarboxylic acids, acid esters, acid anhydrides, ethylene glycol, Low molecular weight alcohols such as 1,2-propanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, hexa Low molecular weight amines such as methylenediamine, xylylenediamine and isophoronediamine, polyester polyols produced by dehydration condensation reaction with low molecular weight amino alcohols such as monoethanolamine and diethanolamine, low molecular weight alcohols, low molecular weight amino alcohols, etc. Open Agents as, .epsilon.-caprolactone, .gamma.-valerolactone cyclic ester to ring-opening polymerization was lactone polyester polyol comprising the lactone and the like, and the like polyesteramide polyols.

  Castor oil polyol is a polyol produced by adding C2-C4 alkylene oxide to castor oil, and its hydroxyl group primary ratio is 10 mol% or more from the viewpoint of curability of the foam raw material. The hydroxyl value is preferably 20 to 350 mgKOH / g. Examples of the alkylene oxide include EO, PO, and latrahydrofuran, which can be added to castor oil randomly or in blocks. These alkylene oxides may be used alone or in combination of two or more.

  The compounding ratio of the castor oil polyol and the other polyol is not particularly limited, but is 15/85 to 50/50, particularly 20/80 to 40/60, and more preferably 25/75 to 35/65 by mass ratio. preferable. If the mass ratio of castor oil polyol and other polyol is 15/85 to 50/50, the foam raw material can be easily cured, has excellent rebound resilience, has a small compressive residual strain, and has sufficient hardness. A polyurethane foam layer having

  As the polyisocyanate, a diphenylmethane diisocyanate (hereinafter abbreviated as “MDI”) system and a tolylene diisocyanate (hereinafter abbreviated as “TDI”) system are used in combination. As the MDI system, 2,2'-MDI, 2,4'-MDI, 4,4'-MDI, or the like can be used. In addition, polymethylene polyphenylene polyisocyanate, urethane modified products thereof and the like can be mentioned. Examples of the TDI system include 2,4-TDI, 2,6-TDI, and modified carbodiimides thereof. The mass ratio of the MDI system to the TDI system is not particularly limited, but the MDI system / TDI system is 95/5 to 55/45, particularly 85/15 to 65/35, and further 75/25 to 75/25. Is preferred. If the MDI / TDI system is 95/5 to 55/45, a polyurethane foam layer that is easy to cure, has excellent impact resilience, has a small compressive residual strain, and has sufficient hardness. it can. As the polyisocyanate, other polyisocyanates other than the MDI system and the TDI system can be used. In this case, the other polyisocyanate is 10% by mass or less when the total amount of the polyisocyanate is 100% by mass, In particular, it is preferably 5% by mass or less.

  As a crosslinking agent, the crosslinking agent currently normally used for manufacture of a polyurethane foam can be used without being specifically limited. As this crosslinking agent, compounds having a molecular weight of less than 500 and having at least two active hydrogen groups, such as low molecular weight alcohols, low molecular weight amines, and low molecular weight amino alcohols, can be used. As the crosslinking agent, low molecular weight amino alcohols, particularly diethanolamine, which have a slow reaction with isocyanate groups, are preferred. These crosslinking agents may be used alone or in combination of two or more. The blending amount of the crosslinking agent is preferably 10 parts by mass or less, particularly 5 parts by mass or less (usually 1 part by mass or more) when the polyol is 100 parts by mass.

  As a catalyst, the catalyst normally used for manufacture of a polyurethane foam can be used without being specifically limited. As the catalyst, tertiary amines, diazabicycloalkenes and salts thereof, organometallic compounds and the like can be used, and tertiary amines are preferable. Tertiary amines include triethylenediamine, triethylamine, tri-n-butylamine, bis (2-dimethylaminoethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine, 1,2-dimethylimidazole, etc. Is mentioned. Examples of organometallic compounds include metal salts of various metals such as tin, lead, and zirconium with organic acids such as octenoic acid and naphthenic acid, such as dibutyltin dilaurate, dibutyltin diacetylacetonate, and zirconium tetraacetylacetonate. Is mentioned. These catalysts may be used alone or in combination of two or more. The compounding amount of the catalyst is preferably 0.03 to 2.0 parts by mass, particularly 0.03 to 1.5 parts by mass, when the polyol is 100 parts by mass. If the compounding amount of the catalyst is 0.03 to 2.0 parts by mass, the foam raw material is easily cured and the moldability is also good.

  As a foaming agent, the foaming agent currently normally used for manufacture of a polyurethane foam can be used without being specifically limited. As the foaming agent, water is frequently used. In addition to this water, there are, for example, two kinds of inert low-boiling solvents and reactive foaming agents. Examples of the inert low boiling point solvent include dichloromethane, hydrochlorofluorocarbon, hydrofluorocarbon, and isopentane. Examples of the reactive foaming agent include an azo compound that decomposes at a temperature higher than room temperature to generate a gas. These foaming agents may be used alone or in combination of two or more. The blending amount of the foaming agent is preferably 1.0 to 5.0 parts by mass, particularly 1.5 to 4.0 parts by mass, when the polyol is 100 parts by mass. When the blending amount of the foaming agent is 1.0 to 5.0 parts by mass, the foam becomes a self-foaming type foam without causing depression or the like on the foam surface.

  As the foam stabilizer, a foam stabilizer usually used in the production of polyurethane foam can be used without any particular limitation. Examples of the foam stabilizer include polydimethylsiloxane / polyalkylene oxide block copolymer and vinylsilane / polyalkylene polyol copolymer. These foam stabilizers may be used alone or in combination of two or more. The blending amount of the foam stabilizer is preferably 3.0 parts by mass or less, particularly 2.0 parts by mass or less (usually 0.5 parts by mass or more) when the polyol is 100 parts by mass.

  For the production of foams to be polyurethane foam layers, antioxidants, anti-aging agents such as UV absorbers, fillers such as calcium carbonate and barium sulfate, internal mold release agents, flame retardants, plasticizers, colorants, anti-glare Various additives such as agents and auxiliaries can be used as necessary.

  The formation method of the polyurethane foam layer is not particularly limited. For example, the foam raw material is formed in a space between the upper mold and the lower mold by a vacuum molding method or the like under the condition that the isocyanate index is 70 to 140, particularly 80 to 120. It can be formed by pouring, reacting and curing. Further, if necessary, the foam raw material and / or the mold can be heated to promote the reaction and curing. Further, the foam raw material uses at least one mixing head, and is preferably injected into the space between the molds to which a release agent is applied, and is usually allowed to react in a temperature range from room temperature to about 70 ° C., for example. It can be formed by curing.

[3] Cross-linked foam layer (1) resin The resin used for forming the cross-linked foam layer is not particularly limited. As this resin, polyolefin resin can be used. As this polyolefin resin, the various polyolefin resin illustrated as polyolefin resin used for formation of the said skin layer and formation of the said base material layer can be used. As described above, polypropylene resin, polyethylene resin, ethylene / propylene random copolymer resin, and ethylene / propylene block copolymer resin are preferable, and polypropylene resin is more preferable. Furthermore, a polylactic acid resin can also be used as the resin. As this polylactic acid resin, the various polylactic acid resin illustrated as a polylactic acid resin used for formation of the said skin layer and formation of the said base material layer can be used.

  The crosslinked foam layer is formed by a crosslinked foamed sheet obtained by crosslinking and foaming a crosslinked foamable resin composition containing a resin, a crosslinking aid and a foaming agent blended as necessary. By providing this crosslinked foam layer, a sufficiently flexible vehicle interior material can be obtained.

(2) Crosslinking aid The crosslinking aid is particularly formulated to crosslink polypropylene resins and polylactic acid resins, and can usually crosslink these resins that are difficult to crosslink. On the other hand, the polyethylene resin can be easily crosslinked without blending a crosslinking aid. Thus, it can be set as the crosslinked foam layer which has the outstanding heat resistance, a moldability, etc. by bridge | crosslinking resin. As the crosslinking aid, a polyfunctional monomer having at least two functional groups in the molecule is usually used.

  As a crosslinking aid, divinylbenzene, 1,6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, triallyl cyanurate, triallyl isocyanurate, N-phenylmaleimide, N, N′-m -Phenylene bismaleimide etc. are mentioned. Of these, divinylbenzene, 1,6-hexanediol dimethacrylate, and trimethylolpropane trimethacrylate are preferred. These crosslinking aids may be used alone or in combination of two or more.

  The crosslinking aid is preferably blended in an amount of 1 to 7 parts by weight, particularly 3 to 5 parts by weight, when the total amount of resins used, particularly polyolefin resin, is 100 parts by weight. If the compounding quantity of a crosslinking adjuvant is 1-10 mass parts, it can bridge | crosslink efficiently.

(3) Foaming agent A foaming agent is normally mix | blended with a crosslinked foaming resin composition. The type of the foaming agent is not particularly limited, and various foaming agents can be used, but a pyrolytic foaming agent, particularly an organic pyrolytic foaming agent is preferable. Examples of the organic pyrolytic foaming agent include azodicarbonamide, benzenesulfonyl hydrazide, N, N′-dinitrosopentamethylenetetramine, toluenesulfonyl hydrazide, azobisisobutyronitrile and the like. These foaming agents may be used alone or in combination of two or more.

  Although the compounding quantity of a foaming agent is not specifically limited, When the sum total of resin and a crosslinking adjuvant is 100 mass parts, it can be normally 1-50 mass parts, and it may be 1-25 mass parts. preferable. When the blending amount of the foaming agent is 1 to 50 parts by mass, the composition can be easily foamed, and a crosslinked foam layer having excellent mechanical properties and heat resistance can be obtained.

(4) Other components Various components can be mix | blended with a crosslinked foamable resin composition other than resin, a crosslinking adjuvant, a foaming agent, and a decomposition temperature regulator. Other components include end-capping agents such as polyfunctional carbodiimide compounds and polyfunctional epoxy compounds, organic peroxides such as dicumyl peroxide, biodegradation accelerators, foaming agent decomposition accelerators, antiblocking agents, and thickening agents. Agent, foam stabilizer, antioxidant, light stabilizer, ultraviolet absorber, lubricant, antistatic agent, softener, plasticizer, pigment, filler, flame retardant, flame retardant aid, antibacterial agent, deodorant, etc. Is mentioned. These other components may be used alone or in combination of two or more.

(5) Preparation of crosslinked foamable resin composition, and its crosslinking and foaming The method for preparing a crosslinked foamable resin composition that is crosslinked and foamed to form a crosslinked foamed sheet is not particularly limited. The resin composition contained and the foaming agent are mixed and then melted at a temperature below the decomposition temperature (foaming temperature) of the foaming agent by various kneaders such as an extruder, a Banbury mixer, a kneader mixer, and a mixing roll. It can be prepared by kneading. Moreover, this crosslinked foamable resin composition is normally shape | molded in a sheet form after melt-kneading.

  Next, the cross-linked foamable resin composition formed into a sheet is cross-linked and foamed. The crosslinking method is not particularly limited, and various methods can be employed. For example, cross-linking by ionizing radiation irradiation and chemical cross-linking using an organic peroxide can be mentioned, and these cross-linking methods can be used in combination. Of these, crosslinking by ionizing radiation irradiation is preferred. Examples of ionizing radiation in this ionizing radiation irradiation include electron beams, X-rays, β rays, and γ rays, and electron beams are often used. Moreover, although the irradiation amount of ionizing radiation is not specifically limited, It is preferable that it is 1-200 kGy, especially 1-100 kGy. By this ionizing radiation irradiation, the molded body is crosslinked, and then heated to a temperature equal to or higher than the decomposition temperature of the foaming agent to foam, thereby forming a crosslinked foamed sheet.

  The foaming method is also not particularly limited, and various methods can be adopted depending on the type of foaming agent. When a thermally decomposable foaming agent is used as the foaming agent, the cross-linked foamable resin composition has a temperature equal to or higher than the decomposition temperature of the foaming agent and higher than the melting point of the highest melting point resin (for example, 190 to 290 ° C). Alternatively, an already molded and crosslinked foamed resin molding can be heated and foamed. Although the heating method in this case is not specifically limited, For example, the various methods using a hot air, infrared rays, an oil bath etc. are mentioned. These may be used alone or in combination of two or more.

(6) Form of crosslinked foam layer The thickness of the crosslinked foamed sheet is not particularly limited, but is 0.5 to 3.0 mm, particularly 0.5 to 2.0 mm, and more preferably 0.7 to 1.5 mm. preferable. If this thickness is 0.5-3.0 mm, it can be set as the crosslinked foam layer which has the outstanding shaping property in the vacuum forming method, and has sufficient mechanical characteristics. Moreover, since it can be set as the crosslinked foam layer which has high durability especially with respect to scratching and piercing, it is suitable as a constituent member of an interior material for a vehicle.

[4] Support layer When the polyurethane foam layer is used as a base material layer, the vehicle interior material is usually manufactured using a metal material or a synthetic resin material to support the base material layer, and is composed of the polyurethane foam layer. A support layer is mounted on the opposite side of the base material layer from the skin layer. Since the support layer receives the polyurethane foam layer, it is formed in a plate shape. Examples of the material used for the support layer include iron, aluminum, magnesium and the like, and iron is preferable from the viewpoint of strength and formability. Examples of the synthetic resin material include thermoplastic resins such as polypropylene and ABS resin. Furthermore, a composite material of a metal material and a synthetic resin material may be used. The thickness of the support layer is not particularly limited, but can be 0.5 to 5.0 mm, particularly 0.8 to 3.0 mm.

[5] Method for Producing Vehicle Interior Material The method for producing the vehicle interior material of the present invention is not particularly limited, and can be produced, for example, as follows.
When the base material layer is made of a thermoplastic resin sheet, the vehicle interior material 100 includes the skin layer 11 and the base material layer 13a, and is usually a crosslinked foam layer between the skin layer 11 and the base material layer 13a. 12 is interposed. Moreover, the uneven | corrugated pattern (texture pattern) 11a is normally provided in one surface used as the design surface of the vehicle interior material 100 of the skin layer 11 (refer FIG. 1). The vehicle interior material 100 includes a multilayer sheet 30 in which a skin material 111 to be a skin layer 11 and a cross-linked foam sheet 121 to be a cross-linked foam layer 12 are bonded together, and a base material 131 to be a base material layer 13. The layers are integrally laminated and bonded by a molding method such as vacuum forming (see FIGS. 3 and 4).

The method of forming the multilayer sheet is not particularly limited. For example, (1) the skin material and the crosslinked foamed sheet are bonded together with an adhesive such as a urethane adhesive and an acetic acid emulsion adhesive, and (2) the skin material and the crosslinked sheet are bonded. (3) Heating one surface of the skin material and / or the crosslinked foamed sheet, and then bonding by pressure bonding, (4) Skin layer on one surface of the crosslinked foamed sheet Various methods such as extruding the composition to be obtained from an extruder or the like and bonding them together can be used.
The multilayer sheet may be formed by any of the above methods (1) to (4), or may be formed by other methods.

  In addition, as described above, the skin layer can be provided with a concavo-convex pattern on one surface which becomes a design surface when it becomes a vehicle interior material, but this concavo-convex pattern may be provided at any time. The uneven pattern is, for example, (1) formed simultaneously with the production of the skin material, (2) formed when producing the multilayer sheet, or (3) formed during the vacuum forming described later. It may be provided at this point.

  When the base material layer is made of a polyurethane foam layer, the vehicle interior material 200 includes the skin layer 11 and the base material layer 13b, and is usually opposite to the surface of the base material layer 13b on which the skin layer 11 is laminated. The support layer 14 is bonded to the surface and laminated (see FIG. 2). In this vehicle interior material 200, foam raw material is injected into a space between the skin material 111 serving as the skin layer 11 and the support plate 141 serving as the support layer 14, reacted and cured, and the skin material 111, the foam 15, The support plate 141 is manufactured by a molding method such as integral foam molding (see FIG. 5) in which the support plate 141 is joined and integrated with each other.

  As described above, the vehicle interior material can be manufactured by a vacuum forming method. Examples of the vacuum forming method include a method in which a heated multilayer sheet is bonded to a base material layer preliminarily formed into a desired shape at the same time as vacuum forming. Further, such vacuum forming methods include a male pulling vacuum forming method, a female pulling vacuum forming method, a vacuum forming method using both of these methods, a method of forming by plug assist etc. simultaneously with male pulling vacuum forming, and upper and lower Various methods such as a vacuum forming method in which a vacuum is drawn at the same time as pressing with a mold are mentioned.

More specifically, when a base material layer consists of a thermoplastic resin sheet, the vacuum forming method described in FIG.3 and FIG.4 is mentioned, for example.
In the vacuum forming method described in FIG. 3, the base material 131 is placed on the mold 22, and then the base material 131 is covered with a softened multilayer sheet 30 heated to 120 to 160 ° C., for example. Then, vacuum forming is performed by sucking with the mold 22 and then demolding the vehicle interior material 100. In this case, the multilayer sheet 30 can be formed by the methods (1) to (3).

  In the vacuum forming method described in FIG. 4, the upper mold 21 sucks and adsorbs the multilayer sheet 30 from the skin material 111 side, and then the upper mold 21 and the lower mold on which the substrate 131 is placed. 22 is a vacuum forming method in which the multilayer sheet 30 and the base material 131 are integrated by sucking from the lower mold 22, and then the vehicle interior material 100 is demolded. In this case, the multilayer sheet 30 can be formed by any one of the methods (1) to (3).

In the case of the vacuum forming method described in FIG. 4, at the time of demolding, (1) the suction of both the upper mold 21 and the lower mold 22 may be released, (2) the suction of the upper mold 21 is released, and The lower die 22 can be kept sucked. In particular, when the base material has air permeability, the followability to the mold shape of the multilayer sheet can be improved by the method of (2) above, and the multilayer sheet and the substrate can be made stronger. Can be pasted together.
In addition, the base material which does not contain a natural fiber can be made into the base material which has air permeability by forming the through-hole for ventilation | gas_flowing by a predetermined method. On the other hand, the base material containing the natural fiber has a ventilation that the base material itself has, particularly when the total amount of the thermoplastic resin and the natural fiber is 100% by mass and the thermoplastic resin is 70% by mass or less. Sex can be used.

  Further, by forming a concavo-convex pattern on the inner surface of the upper mold 21 during vacuum forming, the concavo-convex pattern can be transferred to the skin material. The uneven pattern may be transferred at any stage. For example, when the upper mold 21 is a heating mold, the uneven sheet 30 can be transferred by adsorbing the multilayer sheet 30 to the upper mold 21. Further, it can be transferred when the mold is clamped with the lower mold 22. In transferring the concavo-convex pattern, it is preferable to preheat the surface of the skin material, which becomes the design surface when it becomes the skin layer, to 120 ° C. or higher. If it does in this way, it can be set as the skin layer in which the clear concavo-convex pattern was provided. The preheating temperature is preferably 140 to 220 ° C, particularly 160 to 200 ° C.

  Furthermore, in the case of the vacuum forming method described in FIG. 3 and FIG. 4, the base material 131 may be preformed in advance before being placed on the mold 22, and when not preformed, The substrate 131 may be heated and softened, and then placed on the mold 22 and sucked to be shaped. The multilayer sheet 30 is preferably preheated. Thereby, local expansion of the multilayer sheet 30 can be suppressed and a complicated shape can be followed. The heating temperature of the multilayer sheet 30 is not particularly limited, and is preferably set as appropriate depending on the material and thickness of the skin material and the material and thickness of the crosslinked foamed sheet, but when the skin material becomes the skin layer. It is preferable to heat so that the temperature on the side of the design surface becomes 120 to 220 ° C, particularly 140 to 220 ° C, and more preferably 160 to 200 ° C. When the heating temperature is 120 to 220 ° C., the skin material and the crosslinked foamed sheet can be firmly bonded during vacuum forming, and a vehicle interior material having an excellent appearance can be obtained.

When a base material layer consists of a polyurethane foam layer, the integral foam molding method described in FIG. 5 is mentioned, for example.
In the integral foam molding method described in FIG. 5, the skin material 111 is sucked and adsorbed to the lower mold 32, and then the support plate 141 is interposed between the upper mold 31 and the lower mold 32 to clamp the mold. Next, the foam raw material is injected from the foam raw material injection port 16 provided through the upper mold 31 and the support plate 141, reacted and cured, and the skin material 111 and the polyurethane foam 15 (the base material layer 13b) are obtained. ) And the support plate 141, and then the vehicle interior material 200 is demolded.

  In the case of the integral foam molding method described in FIG. 5, the suction of the lower mold 32 may be released at the time of demolding, or may be kept sucked. In particular, when the polyurethane foam 15 serving as the base material layer 13b has high openness and sufficient air permeability, the ability to follow the inner surface shape of the lower mold 32 of the skin material 111 is maintained by suction. The skin material 111 and the polyurethane foam 15 can be bonded more firmly. Furthermore, the concave / convex pattern can be transferred to the skin material 111 by forming the concave / convex pattern on the inner surface of the lower mold 32 at the time of integral foam molding. The uneven pattern may be transferred at any stage, for example, when the lower mold 32 is heated and the skin material is adsorbed to the lower mold 32. Further, the lower mold 32 can be heated and transferred at the time of clamping with the upper mold 31. At the time of transferring the concavo-convex pattern, it is preferable to preheat the surface of the skin material 111 that becomes the design surface when it becomes the skin layer to 60 ° C. or higher. If it does in this way, it can be set as the skin layer in which the clear concavo-convex pattern was provided. The preheating temperature is preferably 60 to 140 ° C, particularly preferably 80 to 120 ° C.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to the following Example.
[1] Manufacture of vehicle interior materials (see Table 1 describing the material composition of the skin layer, etc.)
Example 1
(1) Skin material 50% by mass of olefinic thermoplastic elastomer (trade name “Miralastomer 7030NH” manufactured by Mitsui Chemicals), 30% by mass of polyolefin resin (ethylene / propylene random copolymer resin, manufactured by Nippon Polypro Co., Ltd., trade name) "NOVATEC EC9"), 10% by mass of polylactic acid resin (manufactured by Nature Works, trade name "Ingeo 4032D"), and 10% by weight of styrene-based thermoplastic elastomer (manufactured by Asahi Kasei Chemicals, trade name "Toughtech H1052") After that, a sheet having a thickness of 0.5 mm was formed by an extruder. Next, this sheet was pressed onto a roll having a texture pattern on its peripheral surface to transfer the texture pattern, thereby forming a skin material provided with the texture pattern on one side. This skin material was used in Examples 1 to 3 and Comparative Examples 1 and 3.

(2) Cross-linked foam sheet 30% by mass of polylactic acid resin (product name “4032D” manufactured by Nature Works) and 70% by mass of polybutylene succinate resin (product name “Bionore 1003” manufactured by Showa Polymer Co., Ltd.) When the total of these resins is 100 parts by mass, 6 parts by mass of a crosslinking aid (triallyl isocyanurate), 9 parts by mass of a foaming agent (azodicarbonamide), and 0.9 parts by mass of oxidation An inhibitor was added, kneaded by a mixing roll at a temperature at which the foaming agent was not decomposed, and pressed at a pressure of 20 MPa to form a sheet. Thereafter, the sheet was irradiated with an electron beam at 13 kGy for crosslinking, and then the crosslinked sheet was put into a hot air foaming furnace adjusted to 240 ° C., heated for 3 minutes, foamed, and a thickness of 1.0 mm. A crosslinked foamed sheet was formed. This crosslinked foamed sheet was used in Examples 1 to 4 and Comparative Examples 1 and 3.

(3) Substrate A kenaf fiber (natural fiber) cut to a length of 70 mm and a polypropylene fiber cut to a length of 51 mm are mixed, mixed by the air lay method, and deposited to form a two-layer web. These webs were entangled with a needle punch to prepare a fiber mat containing kenaf fibers and polypropylene fibers having a mass ratio of 50:50. Then, this fiber mat was heated and compressed at a pressure of 10 kg / cm ² until the internal temperature reached 210 ° C. with a hot plate of 235 ° C., and then cooled to room temperature to produce a 2.5 mm thick fiber board. This fiber board was used as a base material in Examples 1 to 4 and Comparative Examples 1 and 3.

(4) Vacuum forming The surface of the skin material is not provided with a texture pattern, the surface to be joined to the crosslinked foamed sheet is heated to 180 ° C., and the surface of the crosslinked foamed sheet is joined to the skin material. The surface was heated to 120 ° C., and then both were pressed to form a multilayer sheet. Next, by the vacuum forming method described in FIG. 3, the surface of the multilayer sheet is heated so that the temperature of the surface of the skin material becomes 120 ° C., and then placed on the lower mold, and the adhesive ( Hitachi Chemical Co., Ltd., trade name “YA211-1”) is laminated on a substrate coated with a coating amount of 120 g / m ² , and a multilayer sheet is laminated with the cross-linked foam sheet side as the substrate side, The interior material for vehicles provided with the base material layer, the bridge | crosslinking foam layer, and the skin layer was manufactured by pressure-sucking the base material and the multilayer sheet.

Example 2
A vehicle interior material was manufactured in the same manner as in Example 1 except that the polyolefin resin used for forming the skin material was 20% by mass and the polylactic acid resin was 20% by mass.

Example 3
An interior material for a vehicle was manufactured in the same manner as in Example 1 except that the polyolefin resin used for forming the skin material was 10% by mass and the polylactic acid resin was 30% by mass.

Example 4
Others using 30% by mass of olefin-based thermoplastic elastomer, 20% by mass of polylactic acid resin, 20% by mass of styrene-based thermoplastic elastomer used for the formation of the skin material, and a skin material not provided with a texture pattern Formed a multilayer sheet in the same manner as in Example 1, and then heated so that the surface temperature on the skin material side of the multilayer sheet was 180 ° C. by the vacuum forming method shown in FIG. A surface pattern is formed on the surface of the skin material by suction, and then the upper mold and a lower mold on which a substrate coated with an adhesive is placed on the surface in the same manner as in Example 1 The vehicle interior material provided with the base material layer, the cross-linked foam layer, and the skin layer was manufactured by crimping the base material and the multilayer sheet.

Example 5
A skin material having the same composition as in Example 2 and a thickness of 1.0 mm was formed in the same manner as in Example 1. Thereafter, by the integral foam molding method shown in FIG. 5, the skin material is heated so that the surface not provided with the texture pattern is 70 ° C., and the heating surface is directed to the inner surface of the lower mold. And sucked to hold the skin material in the lower mold. Next, a support plate having a thickness of 3.0 mm is placed on the upper surface of the lower mold, and then the upper mold is closed, the foam raw material is injected from the foam raw material inlet, and held at 60 ° C. for 6 minutes to react the foam raw material. And cured to produce a polyurethane foam to be a base material layer, and a vehicle interior material including a polyurethane foam layer, a support layer, and a skin layer was produced.
The foam raw material injection port is formed by communicating a through hole provided in the central portion of the upper mold and a through hole provided in the central portion of the support plate.
The composition of the foam raw material is as follows.
(A) Polyol Polyether polyol (manufactured by Asahi Glass Urethane Co., Ltd., trade name “EL-838”) 22% by mass
Polymer polyol (Asahi Glass Urethane Co., Ltd., trade name “EL-937”) 45% by mass
Polyether polyol: Polyol obtained by random addition polymerization of EO and PO with pentaerythritol (average functional group number 4.0, hydroxyl value 28 mgKOH / g) 3% by mass
Castor oil-based polyol: Polyol obtained by adding EO to castor oil (average number of functional groups: about 3, hydroxyl value: 59 mgKOH / g, terminal primary OH conversion rate: 62 mol%) 30% by mass
(B) Polyisocyanate MDI system: a polyisocyanate obtained by reacting PO and EO at a mass ratio of 80/20 to a mixture of 11% by mass of 2,4′-MDI and 89% by mass of 4,4′-MDI. Polyisocyanate obtained by reacting oxyethylene polyoxypropylene polyol (average functional group number 4.0, number average molecular weight about 8000) 40% by mass
MDI system: mixture of 4.1% by weight of 2,4′-MDI, 32.9% by weight of 4,4′-MDI and 63% by weight of polymethylene polyphenylene polyisocyanate 30% by weight
TDI 30% by mass
The above polyol and polyisocyanate were used in an amount ratio such that the isocyanate index was 85.
(C) Other components Catalyst: 0.4 part by mass, manufactured by Tosoh Corporation, trade name “TEDA-L33”, and manufactured by Tosoh Corporation, trade name “TOYOCAT ET” 0.06 parts by mass Foaming agent: 2.75 parts by mass of water Foam stabilizer: Nippon Unicar Co., Ltd. SZ-1306 1 part by mass The compounding amount of these other components is the compounding amount when the total amount of polyol is 100 parts by mass (the unit is “part by mass”).

Comparative Example 1
The same as in Example 1 except that the olefinic thermoplastic elastomer used for forming the skin material was 60% by mass, the polyolefin resin was 40% by mass, and the polylactic acid resin and styrene-based thermoplastic elastomer were not used. Interior materials were manufactured.

Comparative Example 2
The same as in Example 4 except that the olefinic thermoplastic elastomer used for forming the skin material was 50% by mass, the polyolefin resin was 50% by mass, and the polylactic acid resin and styrene-based thermoplastic elastomer were not used. Interior materials were manufactured.

Comparative Example 3
The same as in Example 1 except that the olefinic thermoplastic elastomer used for forming the skin material was 56% by mass, the polyolefin resin was 22% by mass, the polylactic acid resin was 22% by mass, and the styrene thermoplastic elastomer was not used. Thus, interior materials for vehicles were manufactured.

[2] Evaluation of interior materials for vehicles (1) Presence / absence of flaws The surface of the skin layer of the vehicular interior material is visually observed, and if wrinkles are present or there are wrinkles, the length and depth are determined. confirmed. “◯” in Table 1 means that no significant discoloration or deterioration was observed.

(2) Wrinkle depth The surface roughness of the interior material for the vehicle was measured using a surface roughness measuring instrument (manufactured by Tokyo Seimitsu Co., Ltd., model “Surfcom 570”), measuring length 12.5 mm, measuring speed 0.3 mm. / S, measured under conditions of a cutoff value of 2.5 mm, the grain depth was calculated as the sum of the maximum peak height and the maximum valley depth of the entire measurement section.

(3) Light resistance A sample with a width of 70 mm and a length of 200 mm is cut out from the interior material for a vehicle, and an in-machine temperature of 60 ° C. is obtained with an ultraviolet fade meter (model “U48AU” manufactured by Suga Test Instruments Co., Ltd., with one carbon arc). Ultraviolet rays were irradiated for 1000 hours under conditions of a humidity of 50% RH, a black panel temperature of 83 ° C., and a sample rotation speed of 3 rotations / minute, and the degree of discoloration and deterioration was confirmed. “◯” in Table 1 means that no significant discoloration or deterioration was observed.

(4) Formability The skin layer is observed by visually observing the vehicle interior material from the skin layer side, and floats and peels between the skin layer and the crosslinked foamed layer or polyurethane foam layer, and the uneven shape of the base material layer. The presence or absence of the scale was confirmed. “○” in Table 1 indicates that no floatation, peeling or scaling was observed, “△” indicates that floating, peeling or scaling was observed, and “×” indicates any lifting, peeling or scaling. That means.
The results are also shown in Table 1.

尚、上記の表１において、「ＴＰＯ」はオレフィン系熱可塑性エラストマー、「ＥＰランダム共重合樹脂」はエチレン／プロピレンランダム共重合樹脂、「ＰＬＡ」はポリ乳酸樹脂、「Ｓｔ系エラストマー」はスチレン系熱可塑性エラストマーを意味する。また、「複合材」は、熱可塑性樹脂とケナフ繊維とを用いてなる基材層、「フォーム」は、ポリウレタンフォーム層からなる基材層、を意味する。

In Table 1, “TPO” is an olefin thermoplastic elastomer, “EP random copolymer resin” is an ethylene / propylene random copolymer resin, “PLA” is a polylactic acid resin, and “St elastomer” is a styrene resin. It means a thermoplastic elastomer. “Composite material” means a base material layer made of a thermoplastic resin and kenaf fibers, and “foam” means a base material layer made of a polyurethane foam layer.

  According to Table 1, in Examples 1-5, regardless of the type of the base material layer, and regardless of the method of vacuum forming, no wrinkles occurred and despite containing polylactic acid resin It has excellent light resistance, no discoloration or deterioration, and good moldability. Further, it can be seen that this is a vehicular interior material having a large grain depth and an excellent design.

  On the other hand, in Comparative Examples 1 and 2 in which polylactic acid resin and styrene-based thermoplastic elastomer are not used for the formation of the skin layer, generation of wrinkles is not observed, and there is no problem in light resistance and moldability, but all of the raw materials Is a petroleum-derived material. In addition, although polylactic acid resin is used for the formation of the skin layer, light resistance is not a problem in Comparative Example 3 in which a styrene-based thermoplastic elastomer is not used, but wrinkles are observed and moldability is a problem. I understand that there is.

  The vehicle interior material of the present invention can be used as various vehicle interior materials. Examples of the interior material include a door, an instrument panel, a pillar, a sun visor, a seat back garnish, a console box, a ceiling, a floor, a package tray, a switch base, a quarter panel, an armrest, a dashboard, and a deck trim. It is done.

  100, 200; vehicle interior material, 11; skin layer, 11a; uneven pattern (texture pattern), 111; skin material, 12; cross-linked foam layer, 121; cross-linked foam sheet, 13a, 13b; base material layer, 131 Substrate, 14; support layer, 141; support plate, 15; polyurethane foam, 16; foam raw material inlet, 21, 31; upper mold (upper mold for vacuum forming), 22; mold or lower mold, 32; Lower mold, 30; multilayer sheet.

Claims (6)

A vehicle interior material comprising a skin layer and a base material layer,
The skin layer contains an olefin-based thermoplastic elastomer, a polyolefin resin, a polylactic acid resin, and a styrene-based thermoplastic elastomer,
When the total of the olefinic thermoplastic elastomer, the polyolefin resin, the polylactic acid resin and the styrene thermoplastic elastomer is 100% by mass, the olefinic thermoplastic elastomer is 20 to 70% by mass, and the polyolefin resin is 10 to 50% by mass, 5 to 30% by mass of the polylactic acid resin, and 5 to 30% by mass of the styrene-based thermoplastic elastomer.   The vehicle interior material according to claim 1, wherein the base material layer contains natural fibers and at least one of a polylactic acid resin and a polyolefin resin.   The vehicle interior material according to claim 2, further comprising a crosslinked foam layer between the skin layer and the base material layer.   The vehicle interior material according to claim 1, wherein the base material layer includes a polyurethane foam layer.   The vehicle interior material according to claim 4, wherein the polyurethane foam layer is made of plant-derived materials.   The vehicle interior material according to claim 4 or 5, wherein a support layer is attached to a surface of the polyurethane foam layer opposite to a surface on which the skin layer is laminated.

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